Re: [PATCH 2/3] target/i386: Enable page walking from MMIO memory

[Richard Henderson <richard.henderson@linaro.org>]

On 2/15/24 05:01, Jonathan Cameron wrote:
> -static bool ptw_translate(PTETranslate *inout, hwaddr addr)
> +static bool ptw_translate(PTETranslate *inout, hwaddr addr, uint64_t ra)

You do not need to pass in 'ra' here...

>       flags = probe_access_full(inout->env, addr, 0, MMU_DATA_STORE,
> -                              inout->ptw_idx, true, &inout->haddr, &full, 0);
> +                              inout->ptw_idx, true, &inout->haddr, &full, ra);

... because this                                 ^^^^
indicates a non-fault probe.
A return address is only required for a faulting probe to raise an exception.

> -static inline uint32_t ptw_ldl(const PTETranslate *in)
> +static inline uint32_t ptw_ldl(const PTETranslate *in, uint64_t ra)
>  {
>      if (likely(in->haddr)) {
>          return ldl_p(in->haddr);
>      }
> -    return cpu_ldl_mmuidx_ra(in->env, in->gaddr, in->ptw_idx, 0);
> +    return cpu_ldl_mmuidx_ra(in->env, in->gaddr, in->ptw_idx, ra);
>  }

However the loads do require 'ra' for the io_recompile, as you saw from the backtrace.


r~